The beautiful weather has finally arrived, and you’re eager to get your lawn looking its best. But when you pull the cord on your lawn mower, it sputters and coughs instead of roaring to life. Frustrating, right? A sputtering lawn mower can be a real pain, but it’s usually a sign of a relatively simple problem that you can often fix yourself. This article will guide you through the common causes of a sputtering lawn mower and provide step-by-step instructions on how to troubleshoot and fix them.
A sputtering lawn mower often indicates a fuel-related issue, a problem with the spark plug, or a clogged air filter. By systematically checking each of these components, you can quickly pinpoint the source of the problem and get your mower running smoothly again.
Diagnosing the Problem: Where’s the Sputter Coming From?
The first step is to identify the source of the sputtering. Is it a consistent sputter, or does it happen intermittently? Does the engine try to start but then die immediately, or does it sputter and run rough? Observing the way your mower behaves will give you clues about the underlying issue.
Fuel-Related Issues: Are You Feeding Your Mower Properly?
The most common culprit behind a sputtering lawn mower is a problem with the fuel system.
Here are the key areas to check:
- Old or Bad Gas: If the gas in your mower has been sitting for a long time, it may have gone stale and be preventing the engine from getting the fuel it needs.
- Clogged Fuel Line: Over time, debris can build up in the fuel line, restricting the flow of fuel to the engine.
- Dirty Fuel Filter: A clogged fuel filter will prevent fuel from reaching the carburetor, causing sputtering and stalling.
- Problems with the Carburetor: The carburetor is responsible for mixing fuel and air before it enters the engine. A dirty carburetor, a damaged float needle, or a clogged jet can lead to inconsistent fuel flow and sputtering.
Ignition System: Getting the Spark Right
If the problem isn’t related to fuel, the next area to investigate is the ignition system.
Check the following components:
- Spark Plug: A worn or fouled spark plug can prevent a strong spark, leading to sputtering and misfires.
- Spark Plug Wires: Cracked or corroded spark plug wires can cause a weak spark or no spark at all.
- Ignition Coil: The ignition coil transforms low-voltage electricity into high-voltage electricity to create the spark. A faulty ignition coil can prevent the spark from reaching the spark plug.
Air Intake: Breathing Easy
The engine needs a constant supply of fresh air to operate properly.
Check these areas:
- Air Filter: A clogged air filter restricts airflow, leading to a lean air-fuel mixture and sputtering.
Troubleshooting and Repair: A Step-by-Step Guide
Once you’ve identified the potential source of the sputtering, you can begin troubleshooting and repairing the problem.
1. Addressing Fuel-Related Issues:
1. Fresh Fuel:
* If you haven’t used your mower in a while, the first step is to drain the old gas.
* Use a siphon pump or a gas can with a spout to carefully remove the old gas from the tank.
* Note: Dispose of old gasoline properly at a hazardous waste disposal facility.
* Fill the tank with fresh, high-octane gasoline.
2. Inspecting the Fuel Line and Filter:
* Fuel Line: Carefully inspect the fuel line for any cracks, kinks, or blockages. If you find any damage, replace the fuel line.
* Fuel Filter: Locate the fuel filter (it’s usually a small, cylindrical component near the fuel tank).
* Inspect: Look for any dirt, debris, or discoloration on the filter. If it’s dirty or damaged, replace it.
3. Cleaning the Carburetor:
* Note: This is a more complex procedure that may require specialized tools. If you’re unsure, consult a professional.
* To clean the carburetor, you’ll need to remove it from the engine.
* Carefully disassemble the carburetor and use a carburetor cleaning kit to remove any dirt, debris, or varnish.
* Reassemble the carburetor and re-install it on the engine.
2. Fixing Ignition Issues:
1. Spark Plug Check:
* Remove the spark plug: Use a spark plug socket wrench to remove the spark plug.
* Inspect: Examine the spark plug for signs of wear, fouling, or damage. If it’s worn or fouled, replace it with a new one.
* Gap: Ensure the spark plug gap is set to the correct specifications (check your owner’s manual).
* Test the Spark: Connect a spark plug tester to the spark plug wire and ground it to the engine.
* Note: The spark plug should produce a bright blue spark when the engine is cranked. If there’s no spark, you’ll need to troubleshoot the spark plug wire or the ignition coil.
2. Spark Plug Wire Inspection:
* Check for damage: Carefully inspect the spark plug wire for any cracks, wear, or corrosion.
* Note: If the wire is damaged, replace it with a new one.
* Secure Connection: Ensure the spark plug wire is securely connected to both the spark plug and the ignition coil.
3. Ignition Coil Check:
* Note: If you’ve already checked the spark plug and the spark plug wire, and there’s still no spark, the ignition coil may be faulty.
* Testing: You can test the ignition coil with a multimeter or a spark plug tester. If the coil fails the test, replace it.
3. Keeping the Air Flowing:
1. Clean the Air Filter:
* Locate: Find the air filter housing (it’s usually located near the carburetor).
* Remove: Carefully remove the air filter.
* Clean: If the filter is reusable, clean it using a vacuum cleaner or compressed air. If the filter is disposable, replace it with a new one.
Preventing Future Sputtering: Regular Maintenance
Preventing your lawn mower from sputtering in the future involves some basic maintenance tasks:
- Regular Fuel Changes: Always use fresh, high-octane gasoline in your mower.
- Fuel Stabilizer: Consider adding fuel stabilizer to your gas tank if you’re not using your mower for a long time.
- Air Filter Cleaning: Clean or replace the air filter regularly, as recommended in your owner’s manual.
- Spark Plug Inspection: Inspect and replace the spark plug as needed.
- Carburetor Cleaning: Clean the carburetor annually or more frequently if you use your mower often.
Getting Your Lawn Mower Back in Shape
A sputtering lawn mower can be a frustrating issue, but with a little patience and the right troubleshooting steps, you can get it running smoothly again. Remember to follow the safety precautions, and don’t hesitate to seek professional help if you’re unsure about any of the steps involved. By taking good care of your mower, you’ll be able to enjoy a beautifully manicured lawn all season long.
FAQ
What are the common reasons why a lawnmower sputters?
A sputtering lawnmower usually indicates an issue with fuel delivery, ignition, or air intake. Common culprits include a dirty air filter, clogged fuel lines or carburetor, bad spark plug, or low fuel levels. The sputtering sound usually comes from the engine misfiring, which can be caused by a variety of factors, making it essential to pinpoint the exact issue for effective troubleshooting.
To pinpoint the issue, you’ll need to check the air filter, fuel lines, spark plug, and fuel level. If any of these components are dirty or damaged, they need to be cleaned or replaced. Once you’ve addressed these potential issues, you can move on to other troubleshooting steps.
How do I clean the air filter?
Cleaning the air filter is a simple task that can improve your lawnmower’s performance. First, locate the air filter, which is usually a cylindrical or rectangular component near the engine. Depending on the filter type, it can be either a paper element or a foam element.
For paper filters, tap it against a hard surface to dislodge loose debris. For foam filters, wash them with soap and water, ensuring they are completely dry before reinstalling. Cleaning the air filter allows for proper air intake, preventing sputtering caused by restricted airflow.
What if the fuel lines are clogged?
Clogged fuel lines can restrict fuel flow to the engine, leading to sputtering. To check for clogged fuel lines, first locate the fuel lines connecting the tank to the carburetor. These lines may be visible or hidden beneath a cover.
Visually inspect the lines for any kinks or blockages. If any are present, try to straighten them out or replace the entire line if necessary. You can also try blowing compressed air through the lines to clear any clogs. If the fuel lines appear clean, the issue might be with the carburetor itself.
How do I clean the carburetor?
A dirty carburetor can be a major culprit behind a sputtering lawnmower. The carburetor mixes fuel and air, and if it’s clogged with debris, the mixture will be off, leading to sputtering. To clean the carburetor, you’ll need a carburetor cleaning kit.
Follow the instructions provided with the kit, which typically involves disassembling the carburetor, soaking the parts in cleaning solution, and reassembling them. Be careful not to overtighten the screws. Once the carburetor is clean, it should be properly adjusted, which may require the help of a professional mechanic.
What should I do if the spark plug is bad?
A bad spark plug can also cause your lawnmower to sputter. The spark plug ignites the fuel-air mixture, and if it’s worn or fouled, it may not generate a strong enough spark. To check the spark plug, first remove it from the engine.
Inspect it for signs of wear, such as a worn electrode or a gap that is too wide. If the spark plug appears damaged, replace it with a new one. Make sure the new spark plug is the correct type for your lawnmower. Additionally, ensure the spark plug gap is set correctly for optimal performance.
Is there anything I can do if the problem is with the fuel level?
A low fuel level can also cause sputtering, especially when the lawnmower is running on a steep incline. This is because the fuel pump might not be able to efficiently draw fuel from the tank.
To resolve this issue, simply add more fuel to the tank. If the sputtering continues even after refueling, it’s likely that the fuel pump is malfunctioning, requiring professional repair.
What if none of these solutions fix the sputtering problem?
If you’ve checked all the common causes and your lawnmower is still sputtering, it’s time to consult a professional mechanic. There may be more complex issues with the engine, such as a faulty ignition system or a problem with the engine’s compression.
A mechanic can diagnose the problem accurately and recommend the appropriate solution. Trying to fix complex engine issues yourself without proper knowledge and tools could lead to further damage and unnecessary costs.